no TRANSACTIONS OF THE ILLINOIS 



are about one-tenth of an inch deep and generally scooped out broadly 

 at the bottom in the shape of a gourd. Those which the female makes 

 for her eggs are scooped out still more broadly and the egg at the bottom 

 is often found larger than the puncture at the orifice — thus indicating 

 that it swells from absorption, by a sort of endosmosis, of nutritiv^e fluid 

 from the surrounding fruit, just as the eggs of many saw-flies and of 

 some other snout-beetles are known to do. 



The egg is fully 0.04 of an inch long, nearly oval, not quite three 

 times as long as wide, and of a yellowish color with one end dark and 

 empty when the embryo larva is well formed. The egg-shell is so veiy 

 fine that the larva seems to gradually develop from it instead of crawling 

 out of it; and by taking a matured egg and gently rolling it between 

 the thumb and finger, the young larva presents itself, and at this early 

 age its two little light brown mandibles show distinctly on the head. As 

 soon as this larva hatches it generally goes right to the heart of the fruit 

 and it feeds there around the core, producing much rust-red excrement, 

 and acquiring a tint of the same color. It feeds for nearly a month, and 

 when full grown presents the appearance of Figure 8, d. 



[Figure 8.] 





Apple Curculio \{a) pupa ; (b) larva. 



It diflers so remarkably from that of the Plum Curculio that the two 

 insects can be distinguished at a glance even in this masked form. It is 

 softer, the chitinous covering being thinner and much whiter. It can 

 not stretch straight and travel fast as can that of the Plum Curculio, but 

 curls round with an arched back, joints 4 — 7 being larger than the pre- 

 ceeding. It is more crinkled, each joint being divided into three principal 

 folds much as in the common White Grub. The space between the 

 folds is frequently bluish-black, and there is a very distinct, continuous, 

 vascular, dorsal line of a bluish color. It has no bristles like nenuphar 

 except a few weak ones on the first joint, arising from some ventral 

 tubercles which remind one of feet. The head is yellowish-brown with 

 the jaws somewhat darker, and the breathing pores, except that in fold 

 of first joint, are not easily seen. 



IT TRANSFORMS IN THE FRUIT. 



The fruit of the wild crab containing this larva never falls, and the 

 fruit of our cultivated apples seldom ; and in this respect the effect of its 



